Steelboat question: Rust in the bilge.

[jonasbn]

Hello!

I have no experience with steel hulls but from what I have read interior rust is the first thing to look out for when looking at steel boats. So I looked at this Swedish steel sailing boat from 1982. I know the hull is made by a professional company, but the interiors are often homemade.

I have three concerns about this boat.
1. The steel deck is covered with a teak deck, with some age on it so it's not perfect. I suspect some moisture finds it way to the steel deck. Which should be painted and treated, but I don't know that or the status of the steel deck treatment. Is that a terrible thing?

2. The bilge, where it "connects" to the keel have some rust. Is it normal corrosion or something really bad? See image.

3. The engine had a little bit of standing water under it.

How bad is this? Should I run away or is it all OK?

Thank you in advance
Jonas

 

[pvb]

Welcome to the forums!

If you're seriously interested in the boat, you should get a professional surveyor to assess it for you, preferably a surveyor with good experience of steel boats.

 

[Sandyman]

Don't even bother with a surveyor. Run run run for the hills.

 

[GHA]

Well worth the few quid on kindle..
https://www.amazon.co.uk/Metal-boat-maintenance-yourself-guide-ebook/dp/B0070QRME4

Personally I'd walk away from a steel boat with a teak deck, just a matter of time before you have to rip it off & treat the steel underneath.

 

[Sandyman]

......................or cut the rust away & install a new deck. Paddy next time you're in the yard remind me to show you the decks on TwobiToo. Never seen anything like it.

 

[coenvanwyk]

I could not see the image, so cannot guess at the rust at the keel, but one might be able to sandblast/wirebrush it out, then repaint with a good mastic or epoxy. As far as the deck is concerned, I would not consider putting anything over the steel except paint. That also goes for the inside: we are building Dreamtime so one could, at any time (by undoing screws and bolts) get at the steel and inspect/repair.

In this case, unsless it is a particularly seductive boat or good deal, I would also regretfully pass it by...

 

[peteK]

Plenty of fibreglass boats around why bother with a 36 year old boat.

 

[duncan99210]

When my brother was buying his narrowboat, he was quite taken by one boat and got it surveyed. The surveyor had some sort of gizmo (ultrasound perhaps) that measured the thickness of the steel hull plates: these tests showed that there was significant erosion of the thickness of some parts of the hull, so my brother walked away from that one. I'd want to see similar testing done on the hull of any steel boat I was considering rather than wind up having to replace hull plates a bit down the line.

 

[KellysEye]

I had a steel ketch with teak decks and removed the teak and marine ply under it to stop any rusting. To my surprise the teak and ply were so heavy the boat rose 2 inches in the water when removed. Rusting in the interior is a serious problem the only way to remove rust is to sand blast it and put on two coats of zinc rich epoxy. Use a wire brush and it will leave small specks of steel on area brushed and rust converters do not work, as I found. The way to do it is with a mini sandblaster: http://www.glassetchingsecrets.com/blog/mini-sandblasters/ then the Zinc rich epoxy.

 

[Norman_E]

Something like this, that recovers the grit, may be better. It will need a reasonable sized air compressor to power it. https://www.spraygunsdirect.co.uk/i...8Rcqu95onQBoCrfYQAvD_BwE#sthash.XLuMvU3O.dpbs

 

[John the kiwi]

I am a mechanical engineer and work with steel as my day job.
I used to think a steel boat was my ambition, but now not so much.
If designed right and built right and maintained right, absolutely brilliant.
So ok if you were building from new, and could control the design and build you could get a great boat that might well have say a 35 year service life.

Assessing the quality of the build of a 36 year old boat is not easy.
I would personally want thickness testing using ultrasonic thickness tester mentioned above.
These are cheap and deceptively easy to use, but actually need an expert to use and be confident of the results.
I would also take a jaundiced view of any steel boat that had any water whatsoever on the inside.
It doesn't take much corrosion to lose 1 or 2 mm of thickness, and if you only have 3 mm to start with then there is not a lot between you and the bottom of the sea.

There are so many good 2nd hand fibre-glass boats out there and fibre-glass doesn't seem to have a "use by" date as steel does.(yes i know about osmosis, but how many boats have actually failed due to osmosis?
Cheers
John

 

[KellysEye]

> https://www.spraygunsdirect.co.uk/in....XLuMvU3O.dpbs

That looks really good with the sand recycling it's the one to use for rust inside the boat, thanks for posting it.

 

[Brent Swain]

Teak overlay on any boat,of any material , is a bad idea, for longevity. Yes, buy an ultrasound device, around $125, online. Everyone with a steel boat should have one and learn to use it.

 

[ianabc]

no sand

very toxic dust

copper or nickle slag is safer

 

[Brent Swain]

I just read in the September 2017 issue of Yachting Monthly , about two boats which had their keels fall of ,and sank quickly, taking the lives of 4 on one boat and 3 on another. That is why some of us bother with steel.
A couple of weeks ago, I met a guy who had been sailing his 39 ft stock plastic boat off Mexico, and hit a whale. The boat sank quickly, leaving him in a dinghy .Luckily it was calm, and he had a VHF so he only rowed for a couple of hours. He agreed strongly when we said he should have been in a steel boat, which would have suffered zero damage hitting a whale.
That is why some of us bother with steel.
Read Moitessier's book "The Long Way"
Then read Web Chile's book "Storm Passage" for a comparison between doing such a voyage in steel vs plastic. Moitessier was dry and comfortable the whole way, with dust in his bilges, while Chiles was constantly pumping for his life. Nothing broke on Moitessier's boat , except for a bent bow sprit, when he hit a ship, which he was able to quickly fix, at sea, without losing much time.
That is why some of us bother with steel boats.
Chile's boat had "Yottie" priorities, Bernard's industrial priorities.
Read the recent series in Sail magazine, of someone doing the same route in a stock, plastic, Bob Perry designed, Baba 40. He was soaking wet, and pumping for his life most of the way.
That is why some of us bother with steel boats.
The first 36 I built , pounded on a west coast Baja lee shore, in up to 12 ft surf for 16 days, and was pulled off thru 12 ft surf; no serious damage.
That is why some of us bother with steel boats.
One of my 36 footers was blown across 300 yards of Fijian coral reef, and then dragged back across it, in big surf, by a tug., No serious damage.
It later collided with a freighter in Gibraltar.
No serious damage .
One was blown ashore in a hurricane in Mozambique . No serious damage.
One did a single season transit of the NW passage.
No serious damage. That is why some of us bother with steel.
Some of us would rather deal with chipping and painting, at our leisure, in port, than take the risk of having to deal with pumping for dear life, at sea.
Doesn't matter much if it is in the Atlantic or Pacific . You are just as likely to sink, if you hit a container in plastic, and just as screwed if you end up in a dinghy in rough water at night.
Some of us would rather go in steel, and drastically reduce the odds of such problems.
A Canadian was off the Great Barrier reef a few years back in a stock plastic boat, and his dangerously floppy Yanmar engine mounts broke. The engine punched a huge hole in his hull, and he had to be rescued by a helicopter. The boat sank quickly. Wouldn't have been a problem in a steel hull .Later, he went missing without a trace on a trip from Hawaii to BC ,in the same design plastic boat. Probably less likely in a steel boat.
That is why some of us prefer steel.
The Sleavin Family would have probably survived their tragic collision with a freighter, had their boat been steel.
That is why some of us prefer steel.

Plenty of fibreglass boats around why bother with a 36 year old boat.

 

[Brent Swain]

Another option is to take a one pound ball peen hammer and a centrepunch, and with the boat out of the water, give it good whacks on the centre punch at any suspect points. If it doesn't dent there, you have plenty of metal. Your next step is to clean it thoroughly. An air chisel works well , as does a needle scaler . I sharpened the needles on mine, which helps a lot. Doesn't need much of a compressor.The needle scaler turns it black, then, if you hold it on, the steel gradually goes sandblasted gray. Then you want at least 5 heavy coats of epoxy on. If you are using a colour coat, put it on the last coat of epoxy, wet on wet, for an excellent bond. If it is not wet on wet ,it wont stick. If it is rough ,let it harden for a few weeks before sanding it flush , and giving it another colour coat. If you use epoxy tar ,it will bleed thru the first colour coats . Don't worry. Let it harden for a few weeks and you can put any colour you want over it ,with no bleed thru.

 

[Brent Swain]

I hooked 24 feet of 1 1/4 inch corrugated plastic hose to my mask., Easier than sucking air thru a filtre ,and breathing airrom 24 feet upwind is very safe. One client used a surplus gas mask. No problem.

no sand

very toxic dust

copper or nickle slag is safer

 

[Brent Swain]

Another option for blasting small stuff inside is vacu-blast. You hook a shopvac to a 1 1/2 inch ABS plastic elbow, and run a small blaster thru the side of the elbow. The sand bounces once, and is instantly sucked up by the shop vac . No dust.

 

[Capital_R]

Something like this, that recovers the grit, may be better. It will need a reasonable sized air compressor to power it. https://www.spraygunsdirect.co.uk/i...8Rcqu95onQBoCrfYQAvD_BwE#sthash.XLuMvU3O.dpbs

I just read in the September 2017 issue of Yachting Monthly , about two boats which had their keels fall of ,and sank quickly, taking the lives of 4 on one boat and 3 on another. That is why some of us bother with steel.
A couple of weeks ago, I met a guy who had been sailing his 39 ft stock plastic boat off Mexico, and hit a whale. The boat sank quickly, leaving him in a dinghy .Luckily it was calm, and he had a VHF so he only rowed for a couple of hours. He agreed strongly when we said he should have been in a steel boat, which would have suffered zero damage hitting a whale.
That is why some of us bother with steel.
Read Moitessier's book "The Long Way"
Then read Web Chile's book "Storm Passage" for a comparison between doing such a voyage in steel vs plastic. Moitessier was dry and comfortable the whole way, with dust in his bilges, while Chiles was constantly pumping for his life. Nothing broke on Moitessier's boat , except for a bent bow sprit, when he hit a ship, which he was able to quickly fix, at sea, without losing much time.
That is why some of us bother with steel boats.
Chile's boat had "Yottie" priorities, Bernard's industrial priorities.
Read the recent series in Sail magazine, of someone doing the same route in a stock, plastic, Bob Perry designed, Baba 40. He was soaking wet, and pumping for his life most of the way.
That is why some of us bother with steel boats.
The first 36 I built , pounded on a west coast Baja lee shore, in up to 12 ft surf for 16 days, and was pulled off thru 12 ft surf; no serious damage.
That is why some of us bother with steel boats.
One of my 36 footers was blown across 300 yards of Fijian coral reef, and then dragged back across it, in big surf, by a tug., No serious damage.
It later collided with a freighter in Gibraltar.
No serious damage .
One was blown ashore in a hurricane in Mozambique . No serious damage.
One did a single season transit of the NW passage.
No serious damage. That is why some of us bother with steel.
Some of us would rather deal with chipping and painting, at our leisure, in port, than take the risk of having to deal with pumping for dear life, at sea.
Doesn't matter much if it is in the Atlantic or Pacific . You are just as likely to sink, if you hit a container in plastic, and just as screwed if you end up in a dinghy in rough water at night.
Some of us would rather go in steel, and drastically reduce the odds of such problems.
A Canadian was off the Great Barrier reef a few years back in a stock plastic boat, and his dangerously floppy Yanmar engine mounts broke. The engine punched a huge hole in his hull, and he had to be rescued by a helicopter. The boat sank quickly. Wouldn't have been a problem in a steel hull .Later, he went missing without a trace on a trip from Hawaii to BC ,in the same design plastic boat. Probably less likely in a steel boat.
That is why some of us prefer steel.
The Sleavin Family would have probably survived their tragic collision with a freighter, had their boat been steel.
That is why some of us prefer steel.

This is lovley. I'm from wooden boats background. Have feared the thud of slamming into a container in a nasty trough plenty of times. Have gone to a steel boat for the first time ever.

Being aboard her is weird. The hull (ice class, 20-30 year old 12mm steel plate with a claustrophobic amount of scantlings to be sure she survives the north sea) is thinner than the wood I'm used to.

And the rust worries me. Always there. Never seems to bother the ship though. Anyway, this gave me lovley hope that I'm not too mad.

Thank you.

R.

 

[rogerthebodger]

This is lovley. I'm from wooden boats background. Have feared the thud of slamming into a container in a nasty trough plenty of times. Have gone to a steel boat for the first time ever.

Being aboard her is weird. The hull (ice class, 20-30 year old 12mm steel plate with a claustrophobic amount of scantlings to be sure she survives the north sea) is thinner than the wood I'm used to.

And the rust worries me. Always there. Never seems to bother the ship though. Anyway, this gave me lovley hope that I'm not too mad.

Thank you.

R.

I have a steel boat that I completed for a hull and superstructure and launched in 2009.

Mine was grit blasted before fitting out and painted with many coats of epoxy inside and out. Below the water line I used epoxy tar and this has no damage or rusting.

The are some cracks in the deck paintwork that has allowed rust to get under and lifted the paint in small areas.

I tackle this by chipping the loose rust away then use a stiff cup wire brush in a angle grinder to remove the loose rust and any surrounding paint to show bare bright steel. This is important as ALL the rust must go else it will come back

Following the wire brushing I use Hydrochloric acid to remove the rust into all the crevices. Once I am back to clean "grey" steel I wash with lots of fresh water dry then use phosphoric acid to remove any flash rusting from the very clean metal. I allow the phosphoric acid to dry this gives a protective coating to prevent any further flash rusting so I can paint wit high build epoxy primer then finish as needed.

In the bilge I tend to use ceramic filled epoxy so to give a nice white easy clean surface so its easy to clean and keep water free. White also allows you to see and rust coming through very easy for subsequent repair.